FURTHER STUDY OF FILL SETTLEMENT IN PEAT MARSHES

CONTRARY TO THE EXPERIENCE REPORTED IN THE SIXTH PROCEEDINGS, IT WAS LATER FOUND THAT IN A MAJORITY OF CASES THE FILLS IN PEAT MARSHES WERE VERY GREATLY DISPLACED LATERALLY. THE TYPICAL SITUATIONS ARE ILLUSTRATED BY SECTIONS OF THREE DIFFERENT FILLS. ANALYSIS OF THE DATA FROM 60 CROSS SECTIONS OF ELEVEN DIFFERENT FILLS SHOWED THAT CLAY SOILS ARE VERY MUCH MORE SUBJECT TO LATERAL FLOW WHERE THE DEPTH OF THE DEPOSIT EXCEEDS 25 FEET THAN FOR LESSER DEPTHS. A DETAILED STUDY OF PAVEMENT SETTLEMENT, DEPTH OF PEAT DEPOSIT AND PENETRATION OF FILL, ON A MILE OF ROAD SHOWED VERY DISTINCTLY THE IMPORTANCE OF SECURING FULL PENETRATION OF THE FILL. THE REPORT ALSO DESCRIBES THE IMPROVED METHODS USED BY THE MICHIGAN HIGHWAY DEPARTMENT FOR INSURING ACCELERATED FILL SETTLEMENT BY DYNAMITING.